Peer reviewed

publishedVersion

View/Open

Date

Author

Share

Metadata

Abstract

The purpose of this study has been to describe motor activity data obtained by using wrist-worn actigraphs in patients with
schizophrenia and major depression by the use of linear and non-linear methods of analysis. Different time frames were
investigated, i.e., activity counts measured every minute for up to five hours and activity counts made hourly for up to two
weeks. The results show that motor activity was lower in the schizophrenic patients and in patients with major depression,
compared to controls. Using one minute intervals the depressed patients had a higher standard deviation (SD) compared to
both the schizophrenic patients and the controls. The ratio between the root mean square successive differences (RMSSD)
and SD was higher in the schizophrenic patients compared to controls. The Fourier analysis of the activity counts measured
every minute showed that the relation between variance in the low and the high frequency range was lower in the
schizophrenic patients compared to the controls. The sample entropy was higher in the schizophrenic patients compared to
controls in the time series from the activity counts made every minute. The main conclusions of the study are that
schizophrenic and depressive patients have distinctly different profiles of motor activity and that the results differ according
to period length analysed.